The Experts below are selected from a list of 7578 Experts worldwide ranked by ideXlab platform
Nadezhda Cherednichenko - One of the best experts on this subject based on the ideXlab platform.
-
Composition and structural features of two Permian parareptile (Deltavjatia vjatkensis, Kotelnich Site, Russia) bone fragments and their alteration during Fossilisation
Palaeogeography Palaeoclimatology Palaeoecology, 2019Co-Authors: Daria Kiseleva, Oleg Shilovsky, Evgeny S. Shagalov, Anastasia Ryanskaya, Maria V. Chervyakovskaya, Elizaveta A. Pankrushina, Nadezhda CherednichenkoAbstract:Abstract The Kotelnich vertebrate Fossil site, one of the richest of the Permian period, is characterised by the excellent preservation of Fossil remains due to their burial in a silty anaerobic environment similar to modern peat bogs. The aim of the work is to carry out a comprehensive study of the composition and structure of bone fragments of the Permian parareptile Deltavjatia vjatkensis, as well as that of its embedding rocks, to support further paleoecological and Fossilisation reconstructions. Fossil Bones and their surrounding strata were investigated using optical and scanning electron microscopy, Raman spectroscopy, X-ray diffraction and inductively coupled plasma mass spectrometry (ICP-MS). The carbonate-rich composition of the sediment was found to favour the preservation of the bone apatite. The mineral phase of the bone tissue corresponds to fluorapatite. Organic matrix vibration bands arising on the Raman spectra correspond to C H vibrations of lipids and proteins and possibly cholesterol. The obtained data indicate a high degree of integrity of both bone mineral phase and its organic proteinaceous residue. White blood cell (WBC)-like structures were detected, which possibly could be interpreted as leukocytes. Elemental mapping of Fossil Bones was used to reveal element distribution features (uniform or with zones of apparent enrichment-depletion) and secondary mineralisation zones. Ca, P, Mg, Mn and S are uniformly distributed through the bone; conversely, elevated quantities of Fe are assigned to cracks and large pores formed as a consequence of the decomposition of organic materials. As compared to bone apatite, the authigenic calcite filling of bone porosities is significantly depleted in terms of microelements. The apatite rare earth element (REE) composition of bone tissue, which is inherited from seawater, can be used for paleoreconstructions of redox conditions and water composition. La/Sm ratios (0.4–0.5), high Y/Ho ratios, high uranium content and high La/Yb ratios (2–3) in the bone apatite indicate the absence of recrystallisation during the late stages of diagenesis. A positive cerium anomaly detected in the Bones indicates the presence of an oxidising and possibly alkaline environment during the early stages of diagenesis in shallow coastal basin of the Kotelnich paleolocality. It is shown that 10 to 20% of REE in bone apatite is derived from seawater absorption (hydrogenous source), with the remainder having been derived from host rock (lithogenic) sources.
Manuel Dominguezrodrigo - One of the best experts on this subject based on the ideXlab platform.
-
tracing the spatial imprint of oldowan technological behaviors a view from ds bed i olduvai gorge tanzania
PLOS ONE, 2021Co-Authors: Fernando Diezmartin, David Uribelarrea, Audax Mabulla, Enrique Baquedano, Lucia Cobosanchez, Adrian Baddeley, Manuel DominguezrodrigoAbstract:DS (David's site) is one of the new archaeological sites documented in the same paleolandscape in which FLK 22 was deposited at about 1.85 Ma in Olduvai Gorge. Fieldwork in DS has unearthed the largest vertically-discrete archaeological horizon in the African Pleistocene, where a multi-cluster anthropogenic accumulation of Fossil Bones and stone tools has been identified. In this work we present the results of the techno-economic study of the lithic assemblage recovered from DS. We also explore the spatial magnitude of the technological behaviors documented at this spot using powerful spatial statistical tools to unravel correlations between the spatial distributional patterns of lithic categories. At DS, lavas and quartzite were involved in different technological processes. Volcanic materials, probably transported to this spot from a close source, were introduced in large numbers, including unmodified materials, and used in percussion activities and in a wide variety of reduction strategies. A number of volcanic products were subject to outward fluxes to other parts of the paleolandscape. In contrast, quartzite rocks were introduced in smaller numbers and might have been subject to a significantly more intense exploitation. The intra-site spatial analysis has shown that specialized areas cannot be identified, unmodified materials are not randomly distributed, percussion and knapping categories do not spatially overlap, while bipolar specimens show some sort of spatial correlation with percussion activities.
-
a spatial analysis of stone tools and Fossil Bones at flk zinj 22 and ptk i bed i olduvai gorge tanzania and its bearing on the social organization of early humans
Palaeogeography Palaeoclimatology Palaeoecology, 2017Co-Authors: Manuel Dominguezrodrigo, Lucia CobosanchezAbstract:Abstract Over the past twenty years, early hominin behavioral models have increasingly abandoned social inferences of the behaviors that created the earliest archaeological record. Behavioral reconstructions have focused mostly on the subsistence strategies that conditioned the selection of specific loci (i.e., central-places) and the manipulation and consumption of resources therein (i.e., raw material transport and use and carcass acquisition and processing). Part of the reason why the social component of these behaviors has been marginalized lies in the lack of proper modern analogs and also in a lack of analytical tools to link social organization to subsistence. Spatial analysis of the debris patterns generated by modern foragers (depending on their social organizations) is a potentially useful tool to understand behavior in the past. The application of statistical spatial analyses to the distribution of stone tools and Bones provides an insightful approach to understand socio-economic behavior at any given site, provided a significant part of the archaeological record of a large paleo-surface has been exposed through excavation. This is the case of FLK Zinj and PTK I. A statistical spatial analysis of these sites shows a spatial interdependence between tools and Bones. It also shows that the single dense cluster pattern at these sites is not a preservation issue or a sampling artifact, but the result of a socio-economic organization by early humans that differed from those currently documented among H. sapiens foragers.
-
unraveling hominin behavior at another anthropogenic site from olduvai gorge tanzania new archaeological and taphonomic research at bk upper bed ii
Journal of Human Evolution, 2009Co-Authors: Manuel Dominguezrodrigo, Fernando Diezmartin, Rebeca Barba, Audax Mabulla, Henry T Bunn, Charles P Egeland, Jose Yravedra, E Espilez, A Egeland, Policarpo SanchezAbstract:New archaeological excavations and research at BK, Upper Bed II (Olduvai Gorge, Tanzania) have yielded a rich and unbiased collection of Fossil Bones. These new excavations show that BK is a stratified deposit formed in a riverine setting close to an alluvial plain. The present taphonomic study reveals the second-largest collection of hominin-modified Bones from Olduvai, with abundant cut marks found on most of the anatomical areas preserved. Meat and marrow exploitation is reconstructed using the taphonomic signatures left on the Bones by hominins. Highly cut-marked long limb shafts, especially those of upper limb Bones, suggest that hominins at BK were actively engaged in acquiring small and middle-sized animals using strategies other than passive scavenging. The exploitation of large-sized game (Pelorovis) by Lower Pleistocene hominins, as suggested by previous researchers, is supported by the present study.
Yolanda Fernandezjalvo - One of the best experts on this subject based on the ideXlab platform.
-
hyena as a predator of small mammals taphonomic analysis from the site of bois roche france
Paleobiology, 2018Co-Authors: Jim Williams, Sara Garciamorato, Paola Villa, Peter Andrews, Yolanda FernandezjalvoAbstract:Feeding behaviors may differ between past and current predators due to differences in the environments inhabited by these species at different times. We provide an example of this behavioral variability in spotted hyena (Crocuta crocuta), for which our analysis of a late Pleistocene micromammal assemblage indicates that hyenas preyed upon small rodents, a feeding habit that is rarely observed today among hyenas.The Bois Roche cave site is situated at the edge of a low bluff overlooking the floodplain of a small stream in Cherves-Richemont (Charente, France). The deposits are dated by electron spin resonance (ESR) to about 69.7 ± 4.1 Ka. Excavations at the site recovered Fossil Bones and teeth of large and small mammals, together with hyena coprolites. Water screening of the sediments produced large accumulations of rodent remains with low taxonomic diversity. Small mammal Bones were recovered from hyena coprolites as well. Descriptions of small mammal bone modification, both from the sediments and coprolites, are reported here. The analysis yielded a distinct taphonomic pattern representative of large carnivores (over 30 kg), which differs from any other modern or Fossil predator-accumulated microfaunal assemblage taphonomically analyzed to date. To our knowledge, previous studies of hyena diet have not recorded high concentrations of a single-rodent prey species. Weconclude that the lowspecies diversity of this small mammal assemblage most likely relates to a local abundance of the prey species due to an outbreak in the rodent population, rather than from specialist predator behavior and hunting technique.
-
freshly excavated Fossil Bones are best for amplification of ancient dna
Proceedings of the National Academy of Sciences of the United States of America, 2007Co-Authors: Melanie Pruvost, Yolanda Fernandezjalvo, Reinhard Schwarz, Virginia Correia, Sophie Champlot, Severine Braguier, Nicolas Morel, Thierry Grange, Evamaria GeiglAbstract:Despite the enormous potential of analyses of ancient DNA for phylogeographic studies of past populations, the impact these analyses, most of which are performed with Fossil samples from natural history museum collections, has been limited to some extent by the inefficient recovery of ancient genetic material. Here we show that the standard storage conditions and/or treatments of Fossil Bones in these collections can be detrimental to DNA survival. Using a quantitative paleogenetic analysis of 247 herbivore Fossil Bones up to 50,000 years old and originating from 60 different archeological and paleontological contexts, we demonstrate that freshly excavated and nontreated unwashed Bones contain six times more DNA and yield twice as many authentic DNA sequences as Bones treated with standard procedures. This effect was even more pronounced with Bones from one Neolithic site, where only freshly excavated Bones yielded results. Finally, we compared the DNA content in the Fossil Bones of one animal, a ≈3,200-year-old aurochs, excavated in two separate seasons 57 years apart. Whereas the washed museum-stored Fossil Bones did not permit any DNA amplification, all recently excavated Bones yielded authentic aurochs sequences. We established that during the 57 years when the aurochs Bones were stored in a collection, at least as much amplifiable DNA was lost as during the previous 3,200 years of burial. This result calls for a revision of the postexcavation treatment of Fossil Bones to better preserve the genetic heritage of past life forms.
-
small mammal taphonomy of gran dolina atapuerca burgos spain
Journal of Archaeological Science, 1992Co-Authors: Yolanda Fernandezjalvo, Peter AndrewsAbstract:Abstract The middle Pleistocene sequence at the Atapuerca (Burgos) complex of caves is most completely represented at Gran Dolina. Eleven stratigraphic units are distinguished, seven of which contain abundant small mammal Fossils. These seven units are analysed in order to determine the taphonomic processes present during the accumulation of their faunal remains. The Fossil Bones are extensively broken, both before and after burial. Fossils from six of the units show evidence of localized pre-depositional acid corrosion, which occurred both before and after breakage. In the upper levels, there is also evidence of post-depositional corrosion, both from alkaline and from acid environments of deposition, and in the top level some Fossil Bones also show evidence of weathering and root marks. Images of these modifications, by means of the scanning electron microscope, and their comparison with a large comparative data base of recent modifications from known causal agents, permits the identification of the agents responsible for many of the modifications, and consequently the reconstruction of the sequence of events leading to the accumulation and preservation of the Fossil assemblages. Predators are implicated for some of the breakage and all of the pre-depositional corrosion, which is the result of digestion in the predators' stomachs. In all cases the category of predator can be identified, and at three stratigraphic levels the actual species can be identified with moderate degrees of reliability. Post-depositional corrosion is linked with observations on local acidity/alkalinity of different levels, and the incidence of weathering is linked with evidence for roof collapse over parts of the cave. Taking account of the effects of these processes, particularly the selectivity resulting from predator hunting methods, allows estimates to be made of the degree of bias in the faunal composition and the palaeoecology thereby indicated.
Daria Kiseleva - One of the best experts on this subject based on the ideXlab platform.
-
Composition and structural features of two Permian parareptile (Deltavjatia vjatkensis, Kotelnich Site, Russia) bone fragments and their alteration during Fossilisation
Palaeogeography Palaeoclimatology Palaeoecology, 2019Co-Authors: Daria Kiseleva, Oleg Shilovsky, Evgeny S. Shagalov, Anastasia Ryanskaya, Maria V. Chervyakovskaya, Elizaveta A. Pankrushina, Nadezhda CherednichenkoAbstract:Abstract The Kotelnich vertebrate Fossil site, one of the richest of the Permian period, is characterised by the excellent preservation of Fossil remains due to their burial in a silty anaerobic environment similar to modern peat bogs. The aim of the work is to carry out a comprehensive study of the composition and structure of bone fragments of the Permian parareptile Deltavjatia vjatkensis, as well as that of its embedding rocks, to support further paleoecological and Fossilisation reconstructions. Fossil Bones and their surrounding strata were investigated using optical and scanning electron microscopy, Raman spectroscopy, X-ray diffraction and inductively coupled plasma mass spectrometry (ICP-MS). The carbonate-rich composition of the sediment was found to favour the preservation of the bone apatite. The mineral phase of the bone tissue corresponds to fluorapatite. Organic matrix vibration bands arising on the Raman spectra correspond to C H vibrations of lipids and proteins and possibly cholesterol. The obtained data indicate a high degree of integrity of both bone mineral phase and its organic proteinaceous residue. White blood cell (WBC)-like structures were detected, which possibly could be interpreted as leukocytes. Elemental mapping of Fossil Bones was used to reveal element distribution features (uniform or with zones of apparent enrichment-depletion) and secondary mineralisation zones. Ca, P, Mg, Mn and S are uniformly distributed through the bone; conversely, elevated quantities of Fe are assigned to cracks and large pores formed as a consequence of the decomposition of organic materials. As compared to bone apatite, the authigenic calcite filling of bone porosities is significantly depleted in terms of microelements. The apatite rare earth element (REE) composition of bone tissue, which is inherited from seawater, can be used for paleoreconstructions of redox conditions and water composition. La/Sm ratios (0.4–0.5), high Y/Ho ratios, high uranium content and high La/Yb ratios (2–3) in the bone apatite indicate the absence of recrystallisation during the late stages of diagenesis. A positive cerium anomaly detected in the Bones indicates the presence of an oxidising and possibly alkaline environment during the early stages of diagenesis in shallow coastal basin of the Kotelnich paleolocality. It is shown that 10 to 20% of REE in bone apatite is derived from seawater absorption (hydrogenous source), with the remainder having been derived from host rock (lithogenic) sources.
L Campanella - One of the best experts on this subject based on the ideXlab platform.
-
comparison of nir spectroscopy coupled to chemometrics and derivative thermogravimetry for relative dating of human Fossil Bones
Journal of Thermal Analysis and Calorimetry, 2017Co-Authors: M Tomassetti, Federico Marini, Remo Bucci, Alfredo Coppa, L CampanellaAbstract:The possibility of using near-infrared spectroscopy (NIR) coupled to chemometric exploratory data processing in order to obtain a fast, cheap and nondestructive dating of human Fossil Bones is presented and discussed. The proposed approach has been applied to the differentiation of human Fossil Bones from two necropolises in the Middle Nile (Saggai and Geili). Principal component analysis of the spectral data after suitable pretreatment (standard normal variate + first derivative) allowed to evidence cluster of Bones corresponding to the different antiquity of the samples, thus indicating that the proposed approach can lead to an accurate (although relative) dating of the Fossil samples. Analysis of the PCA loading suggested that the spectral region that are most relevant for the observed differentiation is 4000–4500, 5150–5801 and 6898–7411 cm−1. A confirmation of the reliability of what found using NIR spectroscopy was obtained by comparing the results to those outcoming from the DTG analysis onto the same bone samples followed by PCA, according to a thermogravimetric–chemometric approach already successfully applied in previous researches. Lastly, in order to obtain a more holistic characterization of the samples, a further PCA processing was carried out after “fusion” of data from both analytical techniques.
-
human Fossil Bones archaeometric classification using chemometrics and thermogravimetry influence of skeleton Fossilization and its anatomical parts
Microchemical Journal, 2016Co-Authors: M Tomassetti, Federico Marini, Remo Bucci, Alfredo Coppa, L CampanellaAbstract:Abstract The results of the simultaneous application of thermogravimetry and chemometrics, which allowed differentiating, quickly and inexpensively, finds of very ancient human Fossil Bones (~ 6000 BC), from less ancient ones (some hundreds of years before and after Christ) are here shown. The main purpose of the present research was to highlight if the selection of one or another anatomical part of a Fossil skeleton could influence the differentiation of the antiquity of bone finds provided by the chemometric–thermogravimetric approach. The results obtained have shown that the variability related to the selection of one or another anatomical part of the skeleton is practically irrelevant, if compared to that related to the ancientness of the skeleton investigated.
-
archaeometric classification of ancient human Fossil Bones with particular attention to their carbonate content using chemometrics thermogravimetry and icp emission
Chemistry Central Journal, 2014Co-Authors: M Tomassetti, Federico Marini, L Campanella, Alfredo CoppaAbstract:The potential of coupling chemometric data processing techniques to thermal analysis for formulating an “archaeometric” classification of Fossil Bones was investigated. Moreover, the possibility of integrating the outcomes of this approach with the results of inductively coupled plasma (ICP) emission spectroscopy for an anthropological interpretation of the observed patterns was also examined. Several Fossil bone samples coming from the necropolis of El Geili, in the middle Nile, an important archaeological site, were first of all subjected to thermogravimetric (TG) and derivative thermogravimetric (DTG) analysis and the main steps of the curves were analyzed. This allowed Fossil bone samples to be differentiated, both by means of classical bidimensional and chemometric representations, namely Principal Component Analysis (PCA). In particular, two clusters were observed, attributable to samples of different antiquity. In addition, inductively coupled plasma (ICP) emission spectroscopy showed that the samples in the cluster corresponding to more recent burials are characterized by a higher Zn content, suggesting a more varied diet. The experimental data obtained using thermogravimetry (TG-DTG) allows us to differentiate all the Fossil bone samples analyzed into two separate clusters and to interpret this differentiation in terms of the observed transitions.